yes that is an air hole, about 3cm long and up to the rear for cable and 2cm.The second Image is not the same transducer, it was the third. I have dismantled a total of 4 transducer.

I still want to dismantle a solution for those who do not transducer.Both sides with grinder to grind the surfaces 4mm. Then hand polish and seal.See the enclosed photo. The acoustic window is then about 2-3mm thick.Break through towards the end when possible because of poor installation.The photo is bad do a better tomorrow where the surface looks good.

Sea-Rover,I recognize the idea to grind away most of the housing in front of the elements. But I have found the PVC in the housing doesn't stick well to epoxy, at least not to my epoxy. I use urethane for glueing things to the transducers, but I think urethane is difficult to use for the sound window because of the bubbles. They use vacuum chambers to get rid of the bubbles at the sonar factories, but you seem to have some resources so... How do you optimize the thickness of the epoxy layer for the sound window? Late Sture Hultqvist used an oscilloscope to find the optimal thickness: http://www.geotech1.com/forums/archive/index.php/t-9995.html(I have disassembled four SI transducer and you have done that with four ducers also. Half of those eight ducers have been defective in some way... are we ready for conclusions?)Rickard

Rüdiger,Yes, I have searched for appropriate elements at several piezo manufacturers, but no, they must be ordered as custom made which means very high prices. I don't know who makes the elements for HB and even if I knew I suspect they wouldn't deliver to other customers because of terms in their contract. I have checked with HB, but they don't sell elements, only complete transducers.Rickard

hi rickardi read again the subject, i see you picture.i wonder if when you cut the ducer you cut the array too ?

i think that i go to make a double ducer this winter but i don't want to take out all the elements as sea rover do because i haven't machine tool to make aluminium mountingi see the xray picture again and i have an idea to make a mounting with your solution and adjust the array..........if the ducer are the same and tolerance are good....

Hi abra,I don't cut the piezo elements, I try to cut off the rear end as close the elements as possible without touching them. The elements are very brittle. I think Sea Rover was lucky who could pick out all the elements without breaking any of them. Sea Rover's housings are very advanced, much more advanced than I think is needed. I have read about a method where the elements are potted in a mix with cork crumbs and epoxy. The result is a very strong epoxy bar that acts as housing and sound absorbing back layer at the same time. The sound window must of course be free from cork. This method only requires a way to fixate the elements while the epoxy is hardening. Even the circular downward elements can be treated this way.I myself is tempted to break up one of my doubleducers and arrange with separate SI arrays using the epoxy bar method because the left side in the doubleducer seems bad. Let's see if there is time for it this winter.Rickard

Hope you can interpret them here or read:You're right, it is a delicate work to unpack the piezos.I work with a magnifying glass and the tool Paläontlogie. Break down completely for a transducer I need a good 5 hours. The piezos are not brittle, it's also finally baked Qurz and very hard. I have broken no element. Finally, they must make when sending a lot of energy in motion.

The filler in the PU oscillator is not good as an acoustic window. Is too soft and absorbs the transmission energy. In theory, the transducer reach up to 300 m per side.The devices block off the record at 120m.The two big piezos need to transfer the energy with a hammer art by the PU to PVC. Look to the patent document. There it is drawn.

The cost for the production of aluminum containers are approximately in the range of a transducer.It is easier to process the areas of the transducer.

Here is the picture of the polished transducer. The PVC jacket is partially quite gone.Thus, the transmission energy can be fully gone. detrimental it is very close range because of 5-10 m, the image drowned.at 800 KHz but it is better already.This is more detail to identify from the size of 3-6 cm.

hi sea roveri resume :if i wanted using transducer, to optimise the result i must find a good transducer with no air hole, i must polish the pvc jacket, and adjust the element in window of 0,5 mm as rickard said.in river 800 khz are more important to find ancient site or wreek in archeologyin salt water 800 khz are difficult to use, but double at 455 may give more details.at 800 khz i never past 15 m range and good result are in 8 m max than ducersea rover, do you have sample to compare a polish ducer than other ?

Hi Abra,it is true, you should find the two transducers has no air holes.you can edit them like Rickard writes. The tolerances have to be met. Photos are in the appendix of the transducer polished and unpolished.pol = polishednotpol = not polished455-800 = HDS transducer455-262 = normal transducerAll images with 110m of cable

Sea Rover,Very interesting! I assume you have seen the defects in two of my transducers. SI elements have left their positions and came in contact with the inner wall of the PVC housing. If you grind down the PVC layer to almost nothing there is risk for exposing the element. I have complained several times on the quality control at the production line for transducers. A nasty argument would be, and I hate to be nasty - the transducers are just element containers . You have to retreive the elements and build your own transducer to be sure about performance.Rickard

The writing is unfortunately not with me so quickly. !! Googel Thank !!!!!!

To expand is a hobby-cutters with diamond head, see my picture.This makes it possible to work in tenths of a millimeter.The piezo has to be exposed all around. best original with 2-3 mm filling it. only when the piezo is replaced replace because the rest of PU.The PU is not firmly connected to the copper and piezos. He can be solved with the finger nail when the layer is very thin. The surface of the piezo never touch with a hard tool. if that happens with silver conductive paint coat again.

I've seen your defects, at these short piezos is of course a gross error. You can instead of aluminum, PVC or PPE take to build a container. Acoustic Swamp is the important background in the piezos and the axial alignment recall exactly.A refill the holes with unequal PU can not. there is another layer in the PVC and bad for the sound.Make tomorrow a photo with a broken piezos repair.

i polished my towfish ducer and i'm waiting this week end to go on river, there's wreck on fiew point, i must compare result on same waypoint and same object....if there's good result, i think construct a double ducer polished

hi rickard and sea roveri polished my towfish ducer and today i go on river to compare same object on same waypoint with the ducer at same dephti join picture.i prefere not polished because wood are more visible, i think polished is better for more range and ducer at more distance than ground.but if there's more distance a small object sim's so smaler than not polished ducer and i think you don't see itpicture are done with towfish 60 m cable and hdsi ducer

oh i forget thisi have a problem with the left side in 455i think a wire in left toutch wire ine right...i must reconect the left side in 455the polished ducer can serve for the future experiment to cut ducerin finish i get better result with not polished ducer like this in 800 khza 700 after jC sunken wreck

Abra,These are worrying observations. I think one should be very careful with the polishing/grinding because of two main reasons: firstly, if you reach the copper shield that is painted to the inside of the PVC layer the ground circuits will get in contact with water so the signal ground voltage level may become zero, secondly, the new wall thickness may equal a value that match the conditions for a standing wave which can result in great loss of energy. The ideal thickness is complicated to find because it should fit two different frequencies (455 and 800 kHz).

I think you have a wiring fault in your left SI channel, but it's difficult to say exactly what fault from the images. It may be a short circuit like the one I found in one of my transducers where the piezo was in contact with the transducer ground shield (the painted shield on the inside of the PVC housing).

Do you have two transducer systems with 60 m with cable or do you have one system that you have polished? If you have one system the not polished and polished testings must have been done on different occasions so there is the possibility for disturbing factors, like different water conditions, which may have differed between the tests, especially in a river. I'm just trying to find alternative explanations to save the polishing theory...

hi rickardi have just one ducer mounting in 60 m cable, i polished itfor the left side i think a short circuit whith left /right side 455 in cable (the cable stop propeller during a scan on salt water)i sea some part on my ducer who can make contact in water with ground.before cuting ducer i make an isolation of it with small epoxy paint.i thing polished ducer are good for long range and depht.i'm going to mount a ducer in my repair towfish cable, and mounting first polished ducer isolated on a second cable (20 m) for testing in river.

hi abra,rickard as already said, there can be many causes.important:The surface must be accurately and precisely correct angle to be piezoelectric. for these frequencies to the sound window 1.5 mm to 3 mm thick, it is lampda 1 to 1 / 2

the cable is to give first priority, that it has the correct values​​.falsify the solder something here worth.the speed through the water, driven up or down, Temparatur, etc. ..

interferences, it can also give the water ........will soon post a list of self-mad noise sources

Sea-Rover,I suppose you mean Lambda/4? Sound speed in epoxy and in PVC is about 2500 m/s according to a list I found. This gives Lambda/4 = 0.8 mm at 800 kHz, 1.4 mm at 455 kHz and 2.4 mm at 262 kHz. If 800 kHz is sacrificed 2 mm could be a reasonable compromize to optimize sound window thickness for 455 and 262 kHz and it is within your recommended interval. This is what an amatuer like me believes after some browsing... What do you think, is this correct?Regards,Rickard

uii,because the values are not equally determined.I have slightly different sound values of klein-sonar inc

PVC-P (soft) 80PVC-U (hard) 2250Epoxy 2760PU 1778at the beginning of lambda / 4 where attenuation is then built.otherwise too many signals that are devoted to a troubled image (blurred).the computational burden too many information to the visual representationthe whole sound window is then to 2-4mm thick.lambda is approximately 1 / 2.HB transducers have a two-layer system PU to PVC, respectively. Thermoplastic.make the sound waves on a second envelope with different curing can, so that a damping or piezzo can also be excited, that is a gain.a part of the sound is reflected back and is back on the wall reflects the piezzo goes and gives it an extra kick. in theory, but understandable.for all three frequencies provides a problematic use without compromising testing with much.

I'm building ~Lambden / 4 is reached then layered with epoxy until the attenuation as the image and the resolution.other variant is: build with the pu damping, then with epoxy to create the lambda.test and test and measure against.

in my polished ducer i see the copper shield painted to the inside of the PVC layer the ground.i make an isolation with a PUA varnish and when i take out all cable i see this (that i supose before)i cut cable and re soldering itnext experience these week.....

That cable needs some soldering!! A thin layer with varnish should provide sufficient insulation of the copper shield, I believe. I think it's a miracle you get any image at all! Please, show the results of the repairs when you have done your testing.Rickard

hi abra,Best of all, it again forms a layer of about 2mm and starts grinding again. if the layer is irregular, there are different path lengths in the sound window. this results in a blurred image and irregular.is one possible result-refraction.more interesting would be the mounting position of the piezo. if the layer is very moderate but the copper plate is partially comes forward event. a fault in the assembly of HB.comes from the cable so the transducer or is it the extension?

The longer arrays operating at 262/455kHz very well be, but in more detail at 800kHz, but the image looks a bit coarser. Therefore, I have installed the HD-transducer to obtain a differentiated picture

The two transducers are displaceable in the vertical. This can be adapted to scan the terrain. This makes it possible to 2m from the ground a scan width of about40m away. In addition, resulting in smaller objects, long shadows, which in turn increases the visibility.In very steep bank areas, the country-side chair to be set to ~ 5 °, seaward of the corrected ~ 45 ° down.The effect is understandable upon close inspection of the trigonometric functions.

The length of the cable is currently at 115m. The cable type is the key to the whole thing. It is not worth saving here. Next step is a cable of 230m.

The soldering must be good and clean. A screening of the cable connectionsinevitable.

My fish weighs 10kg and the cable has a guaranteed tensile strength of ~ 18kg.The whole thing is operated without carrier truck. A support cable doubles the water resistanceand the fish pulls up. This effect causes the cable length must be doubled.To draw weight on the cable to be controlled, I've made a tension gauge at the anchorage point. Thus, in the search movement speed after theDraw weight can be adjusted.In compliance with the draw weight and a reasonable rate of ~ 3-4.5 km / h, cable breakage is unlikely.

With a moveable suspension arm, the fish in contact with the ground and an obstaclesimply tipping over and sliding. Of course this is not to be in practice. An accurate Drive and the site search methodology adapted is a must.

Hi Roddy,The tail fins are very effective due to their size, roll and yaw goes back to zero. The turn of course must be selected to be slightly more, because the fish is very stable straight. The U-turns must be made outside of the search field and may not be part of the search grid.The ratio between the length of the fish and the size of the fins results in a very stable position in the water that is the cylinder to the surface is in proportion to each other of from about 1:0.5.The suspension results from the total weight and the weight in the nose and in their length.The fish may be on the air, not horizontal 0 °, otherwise it is unstable in water and it comes to roll and yaw. The horizontal position of 0 ° in the water must be produced with the tensile force and the Flow-pressure the fins, this is achieved with this pressure forces the stable position of the fish.

The fish hangs in the air at about 30 degrees to the back, he stands in the water at around 10 °. At minimum trip, about walking pace it is aligned at 0 °.In my search for small parts and at a resolution of ~ 3cm such a stable position is very important.

The depressor pulls the fish horizontally down. Do not press your nose like a plane, otherwise the sonar signals received by turbulence wrong or faulty.The tail fins are in front to ~ 3 ° slightly raised, producing a perfect glide to the tow point.In the first photo you can see very well how to attract positive tail fin forward.

The cable goes in the water is not straight or angled downward, but always in a parabola. The fish depends on the cable.

I usually look first at 262kHz with the territory. Depending on the size of the object up to 80m wide search. For small parts it's going to 455kHz.When Long-Array 800kHz resolution is high but unfortunately a bit thin in contrast.So I've installed a HD transducer.There are two connectors available with a waterproof seal. The unused connectorIs stowed in the fish.Therefore, I change the plug rather in favor of a better contrast.See Photo 1 and 2

The fish has not undergone the test set forth any changes. Therefore, there are thePhotos in this amount, a little further forward on valid resolution.

Later attempts to optimize the arrays for better or 800kHz.Then there's also back to images

The depression-wing, I have assembled for the benefit of handling fixed. An attachment to the towing arm would be a lot better, because it reacts to any change in speed.Large velocity steeper angle ...... slow ride flatter angle.These photos in the previous post.

I'm usually constant at 3.5km / h, therefore, the fixed wing, photo 3

As a control, the allowable tension on the cable, I hooked a pocket balance, photo 4

The cable is a CAT-6 type. Shielded twisted and 3x2Paare. Very good electrical. Values.Cable diameter is 9mm, without supporting rope.The connectors are LEMO and are pressure resistant up to 200mBut are relatively expensive, but the electrical properties are worth it.

during a test (polished ducer) i crash the towfish,i take the ducer and cut iti find a big difference in cotation between left and right arrayin this picture whe can see the arraysit's an hdsi ducer 455 / 800 khzimpossible to make a double ducer with this differencei have question for sea roverwhat type of epoxy are you using to make your array ?for this you say 3 mm of epoxy outside the array, it's right ?

This is yet another observation of a terribly bad transducer. Most dissected transducers have been defective beyond what's acceptable.

Greg, what do you think, is the production management aware of this?

Rickard

PS Today I was made aware a competitor has released a Doubleducer that can be run at 455kHz (and probably other frequencies too). It can most likely be interfaced with any Humminbird SI model with some soldering and a Y-cable arrangement with a downward 200 kHz ducer. A convenient and safe way to get ones own Doubleducer system.

I have been concerned about the transducer quality control since I saw your first posts discovering the problems. The more of these that are cut into, the more we see how bad the problem really is. I am thinking the only way to determine if you have a good transducer is to cut into it or get it xrayed from serveral different angles.

It looks likely that the reason abraquelebout couldn't see the wreck with his towfish is that he has a bad tranducer to begin with.

It is pretty frustrating that no mattter how good you are at creating towfish or how good your mounting is on your boat, and no matter how good you are at the settings, you may have bad images because of a poor quality transducer!!

Have you emailed any of these pictures to Humminbird customer support?

No I haven't sent any pictures to the support. Perhaps I should contact the management directly? But I believe they know since this forum should be a rather important source for feedback.

The product I'm thinking of is the Lowrance LSS2, the transducer, not the control unit and the rest of the system. They have abandoned 800 kHz for the lower 455 kHz and still have at least the same horizontal resolution and longer range in comparison to a standard transducer. This is the opposite strategy to Humminbird's. HB sells "Compact SI" transducers which have even worse resolution performance than the standard SI transducers have. But of course, better performance means higher price, something that must be accepted.

Thanks Rickard....I would be happy with a sindgleducer that I knew was good quality.

I had seen the LSS-2 being advertised but didn't realize it was 455khz only. Do they still have a dedicated DI element in this one, or is this strictly to get better SI range? I know the SI range has been a weakness in the LSS-1.

Let us know how it works out if you decide to try one.

P.S. Just did a little research, and it looks like they still have the dedicated DI, but they don't say a lot about it. I am wondering if they run the DI at 800kzh and the SI at 455khz to get rid of the interference problem they were having between the 2 elements. Could always do a little experimenting and splice a Humminbird extension cable to the Lowrance extension cable. That way the original transducer cable would be intact and the transducer could be sold if it didn't work out. Haven't been able to find a wiring diagram of the cable yet.

Hi Abra,That does not look good. I think soon there are no transducers are mounted correctly.You can take the same type of epoxy for the boats.Resin for polyurethane acoustic windows take.As on the drawinggreeting

hi every body thanks a lot sea roverwhat are you caled "Resin for polyurethane acoustic windows" ?i think i go on way as you do, making self made array....

to ask something about this cuted ducer, i get it since a verry long time, it make my first towfish, and i find lot of thing with it... it'was a good ducer and work verry well, it's ok for is used as a simple ducer and it's verry bad to trasform it in double, or polishedi must take it is array for a second life.no i don't tell it's a bad ducer, more good sample in my post are made with it...

Thanks Rickard....I would be happy with a sindgleducer that I knew was good quality.

I had seen the LSS-2 being advertised but didn't realize it was 455khz only. Do they still have a dedicated DI element in this one, or is this strictly to get better SI range? I know the SI range has been a weakness in the LSS-1.

Let us know how it works out if you decide to try one.

P.S. Just did a little research, and it looks like they still have the dedicated DI, but they don't say a lot about it. I am wondering if they run the DI at 800kzh and the SI at 455khz to get rid of the interference problem they were having between the 2 elements. Could always do a little experimenting and splice a Humminbird extension cable to the Lowrance extension cable. That way the original transducer cable would be intact and the transducer could be sold if it didn't work out. Haven't been able to find a wiring diagram of the cable yet.

Bob,

or anyone, anything new on wiring in the LSS-2 transducer cable? It really would be interesting to see if the LSS-2 can be used as a doubleducer for the HBs.

Rickard,I sent an email to Lowrance customer service requesting the pin-out for the Lss-2 transducer......after quite a delay I got a response that said "sorry, but we do not have that information at this time."

I just ordered the LSS-2 transducer and have to wait for two weeks for delivery. In the mean time I will figure out how to disclose the circuits. There are nine pins. The left, right and downward (DI) channels probably have their separate circuits with individual grounds. This could be the case also for the temp channel. The last pin could be a ground pin for a drain wire, perhaps. This is all guesswork and all testing with the unit connected will be quite risky. All I know in advance is the only circuit with less than infinite resistance is the temp channel. I would appreciate any advice on how to proceed with this.

Rickard

PS The international manual for the LSS-2 states the frequency is 455 kHz, the US manual says it's 455 AND 800 kHz. The LSS-2 is thus probably compatible with all HB units once the interfacing issues are cracked. DS

PS The international manual for the LSS-2 states the frequency is 455 kHz, the US manual says it's 455 AND 800 kHz. The LSS-2 is thus probably compatible with all HB units once the interfacing issues are cracked. DS

Rickard, I was wondering if they are using 455khz for the SI and 800khz for their DI to try to prevent the interference the DI causes in the SI beam......couldn't find anything that documents it very well.